1. Field of the invention
The present invention relates to a skin washing apparatus using a brushless DC electric motor, and more particularly to a skin washing apparatus using a brushless DC electric motor by which facial skin can be optimally washed with minimum power consumption by applying a brushless DC electric motor and applying a forward/reverse operation mode at a predetermined angle at the same time.
2. Description of the Prior Art
In general, beauty of a human body is desired without distinction of age and sex and skin should be managed cleanly and systematically to achieve beauty of a human body, in particular, beauty of skin. To this end, skin care devices have been developed and used in various forms according to parts of the human body where the skin care devices are to be used to correspond to characteristic of the body parts.
In particular, methods for managing facial skin of the human body basically include skin care with cosmetics, and functional cosmetics are currently used for skin care.
Meanwhile, various apparatuses for washing facial skin have been proposed, which apparatuses largely correspond to a method of simply generating rotations when a washing brush is rotated, and a method of generating vibrations. Two vibration methods are generally applied to generate vibrations.
The method of rotating a washing brush simply through rotation of a motor is generally known in the art, and thus a further description thereof will be omitted. Hereinafter, a method of employing an eccentric disk and the basic concept of a motor which rotates in a spiral arc form will be briefly mentioned.
First, FIG. 1 shows a general eccentric rotation type vibration motor. As shown, a PCB positioning part is formed in a lower case 2 so that a PCB circuit board 6 may be positioned in the PCB positioning part 1. A permanent magnet 3 is fixedly installed at an upper portion of the lower case 2. A rotator 7 is rotatably installed above a stator, that is, the permanent magnet 3 while a gap being maintained between the stator and the rotator 7, and the rotator 7 includes a coil 8 and a segment 9 which are largely designed to be eccentric. In addition, the rotator 7 has an eccentric mass at one side thereof and functions as an eccentric mass.
The vibration motor requires a rectifying circuit by which coils through which current flows are changed according to a position of a rotator to rotate the rotator in a predetermined direction. A current circuit of a coin type vibration motor includes a brush 5 electrically connected to the PCB circuit 4 of the PCB circuit board 6, and a segment 9. In the principle of rotating the coin type vibration motor, the DC power input from the PCB circuit 4 flows to the coil through the segment 9 contacting the brush 5. Then, the segment 9 contacting the brush 5 is changed by the rotating rotator, rectifying the current.
Second, there is a vibration method employing a voice coil, which is most widely used in hard disk drives, and a schematic principle thereof will be described by using a hard disk drive. As shown in FIG. 2, a magnetic disk 110 is rotatably mounted to a spindle motor (not shown) installed in a base frame 100, a magnetic head actuator 200 driven to be rotated about a pivot shaft P to fly a magnetic head h on the disk 110, and a cover frame (not shown) coupled to the frame, for protecting the disk 110 and the magnetic head actuator 200 and interrupting introduction of foreign substances. Reference numeral 120 is a circuit driving part for transferring a signal between a main circuit board (not shown) interfacing with a device body such as a computer and the magnetic head h and controlling driving of the magnetic head actuator 200.
As shown in FIG. 3, the magnetic head actuator 200 includes a voice coil motor (VCM) 210 having a lower yoke 211 and an upper yoke 212 to which a pair of magnets M are attached to face each other, a swing arm 220 rotated about the pivot shaft P by the voice coil motor 210 as a head stack assembly (HSA), a suspension 230 supported by the swing arm 220 and having a magnetic head h at a tip end thereof, and a bobbin 230 branched to correspond to the swing arm 220 and on which a coil is wound to be located between the magnets M.
The voice coil motor 210 is a kind of driving motor for rotating the swing arm 220 to move the magnetic head h to a desired position on the disk and uses Fleming's left hand rule, that is, a principle of generating a force when current flows through a conductor. A force is applied to the bobbin 230 to rotate the bobbin 230 by applying current to the coil 231 located between the magnets M. Accordingly, as the swing arm 220 branched to correspond to the bobbin 230 is rotated, the magnetic head h supported at an end of the swing arm 220 flies radially on the rotating disk 110 to search for and access a track, and the accessed information is signal-processed by the circuit driving part 120 and is recorded in or output from a computer.
Meanwhile, although the motor currently applied to skin washing uses a rotary motor or systems employing arc-form, spiral, reciprocal motions, the size of the product increases and current consumption also increases, reducing a life span of the battery.
Further, since a motor is rotated only in one direction according to the related art, the skin washing brush is also rotated in one direction when a washing liquid is applied to a face, resulting in a limit in the washing liquid uniformly contacting the skin.